In general, a conventional DIP switch is made of plastic material and formed integrally with plastic housing. A number of selectors are disposed side-by-side on a top or side surface of housing. A number of pins, electrically connected to selectors, are provided on bottom surface of housing. Pins may insert into a number of corresponding holes in a circuit board for tightly securing switch on circuit board.
There is a disadvantage that because switch is plastic and an opening is provided on circuit board corresponding to selector DIP switch for permitting a user to use a finger or a pointed object like a ball-point pen to set DIP switch selectors in order to choose a desired function, an EMI may be generated from other devices on an enabled circuit board. As a result, EMI may interfere with the operation of switch. Further, EMI may emit from opening to interfere with other adjacent devices.